The apparatus in accordance with the invention relates to building construction apparatus and particularly to apparatus used in forming reinforced concrete members or slabs, and to supports for positioning a reinforcement bar while concrete is poured around it and then allowed to set. More particularly, it has special application to structures which are sometimes referred to as "chairs" for supporting reinforcement bars during the fabrication of reinforced concrete panels, slabs, or walls. The reinforced concrete panel being formed is separated from the floor or supporting surface by "spray sealing" or by a form liner. Such form liners are typically made of polystyrene and are contoured to produce a decorative effect on the formed concrete surface. Such decorative effects may include surfaces resembling a brick wall, a stone wall, logs or other aesthetically desirable contours. Form liners of this general type are manufactured by Labrado Form Liner Company, of Laguna Hills, Calif. The chairs remain within the cast concrete with the axial extremities or feet thereof extending out of the cast concrete toward the cooperating form liner.
Various apparatus including wire structures have been provided. Such structures have not been wholly satisfactory because the support was unstable, or left an unsightly appearance on the finished product. Some structures which have been known heretofore have been unsatisfactory because of the difficulty of breaking off the feet of the support apparatus which extend through the face of the finished product and create an unsightly appearance if not properly severed. Some support structures have been unsatisfactory because of bleeding and particularly rusting which discolors the concrete adjacent to the support. The latter problem is most acute with metal supports which had been chiseled or broken off so that there is no rust inhibiting coating, such as zinc, in the area that is broken off.
Another problem with the known supports is that frequently they are relatively bulky to ship as well as to carry to the work site. Still another problem with known apparatus is that they are vulnerable to producing voids in the cast concrete which substantially weakens the concrete and compromises the structural integrity of structures manufactured with such supports.
It is an object of the invention to provide apparatus which is collapsible for easy shipment.
It is another object of the invention to provide apparatus which provides a very stable support for an associated reinforcing rod, despite the destabilizing effects of concrete pouring over the reinforcing rod and the supports therefor.
It is another object of the invention to provide apparatus which will be contoured in a manner which will minimize the formation of voids in the cast concrete which would compromise the physical characteristics thereof.
Another object of the invention is to provide apparatus which not only will be stronger than known apparatus, but will also enable the user to easily break off the feet thereof, after setting of the concrete, to produce an aesthetically satisfying appearance.
Still another object of the invention is to provide apparatus which is simple and inexpensive to manufacture and which will reduce the time to form cast concrete structures and thereby reduce the total construction cost.